Toothbrush head for improved plaque removal

ABSTRACT

The invention is directed to an improved toothbrush head designed to efficiently remove biofilm from dental surfaces. Advantageously, the improved toothbrush head is designed to be effective against the development of both caries and periodontal disease. The improved toothbrush head is designed so that at least one side bristle on each lateral side of the toothbrush head (for preventing caries) and at least one center bristle from the toothbrush head (for preventing periodontal disease) are removed or reduced in length relative to the other bristles of the toothbrush head.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present patent application claims the benefits of priority of U.S. Patent Application No. 62/955,013, entitled “TOOTHBRUSH HEAD FOR IMPROVED PLAQUE REMOVAL” and filed at the United States Patent and Trademark Office on Dec. 30, 2019, the content of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to the field of toothbrushes. Specifically, the invention is directed to an improved toothbrush head designed to efficiently remove plaque from teeth.

BACKGROUND OF THE INVENTION

Tooth brushing remains the most popular means of oral cleansing in the world [1] with the intention of removing dental plaque and thereby preventing caries and periodontal disease [2].

Although there have been several modern toothbrush designs [3], studies show that high levels of residual dental plaque still persist after tooth brushing [4]. For example, Ebel et al. shows persistent plaque at 69% in their study testing following tooth brushing in adults.

Dental plaque is typically associated with a pathological process in dental caries and periodontal diseases [5]. Plaque is a white or yellowish biofilm that is formed by bacteria on the teeth, whereas dental calculus is formed by the mineralization of minerals in saliva on soft plaque [6].

Dental surfaces associated with the caries hierarchy of attacks defined the specific sites for residual dental plaque locations. For example, and as illustrated in FIG. 5, pits and fissures are first to be affected as lesions tend to start deep in the center of the fissure where dental plaque is likely to be concentrated. Interproximal residual plaque tends to subsequently form in the contact areas creating further lesions, as illustrated in FIG. 6. Finally, smooth free surfaces are impacted as residual plaque forms at the gingival level as shown in FIG. 7.

Dental niches where plaque gets stagnated drive the calculus distribution [7] with a symmetrical arrangement on teeth, more on natural crevicular crevasse facial surfaces on maxillary molars and lingual surfaces of mandibular of anterior teeth [8]. For example and as illustrated in FIG. 8, these natural crevasses form a space between the gingival tissue and the tooth tissue approximately 2 to 3 mm in size where the dental plaque may become calculus. The lingual surfaces of the mandibular anterior teeth (as shown in FIG. 9) are commonly the first ones to be covered by calculus due to the sublingual gland and mineral mixed to stagnated dental plaque.

More recently, a NAHES III study evaluated 9,689 Adults in the United States between 1988 and 1994 and observed that 91.8% of the subjects had a noticeable calculus and 55.1% had subgingival calculus [9].

Since 1986, there has been continued interest in the effectiveness of various toothbrush designs with the intention of reducing calculus in users. Recognizing the public's ineffectiveness at plaque removal measures, manufacturers have attempted to maximize toothbrush efficiency [3].

The classical manual toothbrush with a flat head, hog bristles and wooden or ivory handle has been available for over a century [10]. In 1986, Frandsen [11] recommended that a good toothbrush have following characteristics: a small head to facilitate access; wide long handle for easy grip; 0.2 mm×10 mm soft nylon or polyester bristles (filaments not larger than 0.009 inches in diameter) with rounded bristle ends to minimize gingival damage; and a multi-tufted, straight-trimmed brush head for optimal cleansing effect. Characteristics were re-conducted more recently at a European Workshop [12] and preventive dentistry publications [13].

From a commercial standpoint, a lot of time and energy has been spent by toothbrush manufacturers developing manual toothbrushes. Referring now to FIG. 10, prior art toothbrush heads that are currently available on the market are show. As may be appreciated, most modern toothbrushes tend to include extra bristles and/or have irregular bristles heights. These toothbrush heads may comprise irregular bristle heights meant to help clean pits and fissures along the teeth. However, other key sites necessitating cleaning may not be reached.

It has been found that some designs are not optimally shaped for proximal access since anatomically, the proximal space between adjacent teeth is a triangle shape and central bristle arrangements are a circle (or “ball”). Physically, the ball of a bristle is typically too large to fit within the proximal space and will be blocked by the adjacent proximal labial surfaces. In other words, the central part of the bristle is simply too large thereby limiting the ability of certain bristles to properly clean free surfaces. Referring now to FIG. 11, the darker bristles of the illustrated prior art brush create an overlap effect which does not effectively clean surfaces.

Another prior art example of a prior art toothbrush head is illustrated in FIG. 12. In this example, the toothbrush head is shaped in the form of a FIG. 8 in order to orient the brushes. The reduction in the number of bristles from this type of toothbrush head is extreme and does not clean teeth in an optimal way.

There is therefore a need for a toothbrush head comprising modified bristles configured to reach stagnated dental plaque area such proximal and pits/fissures surfaces for caries prevention and to reach abounded calculus areas such lingual surfaces of anterior teeth for periodontal disease.

SUMMARY OF THE INVENTION

The shortcomings of the prior art are generally mitigated by an improved toothbrush head that allows for better cleaning of interproximal surfaces and natural crevasses in order to prevent or minimize the development of caries and prevent periodontal disease.

The present invention is directed to a toothbrush head, being connected to or connectable to a toothbrush grip handle, the toothbrush head comprising a face having a longitudinal and lateral axes and a plurality composed of a first, a second and a third type of tufts of bristles extending perpendicular to the face and each having a length, wherein the first type of tufts of bristles is located close to perimeter of the face along the lateral axis, the second type of tufts of bristles is located close to center of the face along the longitudinal axis, the third type of tufts of bristles is located to in areas of the face not comprising the first or second types of tufts of bristles and the first and second types of tufts of bristles have shorter lengths than the lengths of the third type of the tufts of bristles.

In another aspect of the invention, the third type of tufts of bristles encircle the second type of tufts of bristles, the length of the third type of tufts of bristles are at least 1.0 cm, while the first type of tufts of bristles has a shorter length than the second type of tufts of bristles. The bristles of the first type of tufts of bristles may have a width between 3.2 mm and 3.5 mm. The bristles of the second type of tufts of bristles may have a width between 3.2 mm and 3.5 mm.

In another aspect of the invention, the toothbrush head comprises four tufts of bristles of the first type and/or of the second type. The tufts of bristle of the second type may define a triangular cavity encircled by the third type of tufts of bristles, the triangular cavity being from 1.5 to 2.5 mm deep compared to the length of the longest tuft of bristle of the third type and being from 2.0 to 4.0 mm long along the longitudinal axis. The cavity may additionally be about 1.0 mm deep from the length of the longest tuft of bristle of the third type and being about 2.0 mm long along the longitudinal axis. The location of the first and second types of tuffs of bristles may be symmetrical about the longitudinal axis.

The present invention is further directed to a method for effectively brushing teeth, the method comprising applying toothpaste in a cavity of a toothbrush head, the cavity being located near a distal end of the toothbrush head and made by extending tufts of bristles encircled by longer extending tufts of bristles, the longer extending tufts of bristles being configured to prevent slipping upon contact with the tooth, pressing the tufts of bristles comprising the toothpaste over teeth, and brushing for at least 30 seconds.

In another aspect of the invention, the method further comprises removing any applied toothpaste protruding out of the cavity prior to pressing the tufts of bristles over the teeth and stopping the brushing when the fluoride concentration of the toothpaste over brushed teeth is between 250 to 500 ppm.

Other and further aspects and advantages of the present invention will be obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the invention will become more readily apparent from the following description, reference being made to the accompanying drawings in which:

FIG. 1 is a perspective view of an embodiment of a toothbrush head in accordance with the present invention;

FIG. 2 is a side view of the embodiment of the toothbrush head shown in FIG. 1;

FIG. 3 is a perspective view of an alternative embodiment of a toothbrush head in accordance with the present invention; and

FIG. 4 is a side view of the embodiment of the toothbrush head shown in FIG. 3.

FIG. 5 is a top plan view of a molar and premolar.

FIG. 6 is a side view of teeth.

FIG. 7 is a side perspective view of molars and premolars.

FIG. 8 is a side perspective view of molars and premolars.

FIG. 9 is a top perspective view of incisors, premolars and molars.

FIG. 10 is a side view of prior art toothbrush heads.

FIG. 11 is a side view of a prior art toothbrush head brushing teeth.

FIG. 12 is a front view of a prior art toothbrush head.

FIG. 13 is a side perspective view of molars and premolars.

FIG. 14 is a side view of a prior art toothbrush head brushing teeth.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A novel toothbrush head for improved plaque removal will be described hereinafter. Although the invention is described in terms of specific illustrative embodiments, it is to be understood that the embodiments described herein are by way of example only and that the scope of the invention is not intended to be limited thereby.

The invention presented manifests itself as a particular distribution of bristles on the head of a manual toothbrush head 10. This invention may be adapted to all types of toothbrush heads.

This invention consists of modified bristles 20 within a toothbrush head 10 which can be applied to all types of toothbrushes. More specifically, the novel design of the toothbrush head 10 of the present invention involves the distribution of modified bristles 20 having a length which is reduced relative to surrounding bristles 30 in the head.

The unique design of the toothbrush head, which will be described further below, may advantageously allow the simultaneous prevention of caries and periodontal disease. More specifically, the present invention as illustrated in FIGS. 1 to 4 utilizes units of bristles or parts of bristles having a shorter length such as to be more effective in the prevention of caries and periodontal disease.

FIG. 1 shows a first embodiment of the novel toothbrush head 10 in accordance with the present invention. The toothbrush head 10 includes shortened bristles 20 near sides 12 and near a center portion 14 of the toothbrush head 10. The shortened length of the bristles 20 may be further appreciated from FIG. 2, which is a side view of the toothbrush head 10, as shown in FIG. 1.

Referring now to FIG. 3, a second embodiment of the novel toothbrush head 10 in accordance with the present invention is illustrated. In this embodiment, the length of the shortened bristles 20 is reduced relative to the bristles shown in FIGS. 1 and 2. The shortened length of the modified bristles 20 may be further appreciated from FIG. 4, which is a side view of the toothbrush head 10 shown in FIG. 3.

As will be appreciated by one of skill in the art, the lengths of the bristles may be adapted to suit the particular needs of individual patients.

In certain embodiments, the length of the modified bristled 20 may be configured in accordance with the natural inter-dental embrasures in humans. The length of the natural dimensions of the triangular regions representing the natural inter-dental embrasures in humans was determined in an experiment further detailed herein.

In order to measure the natural inter-dental embrasures, a precise triangle must be measured without overlapping onto the surfaces of the adjacent teeth. Accordingly, a white molten wax may be applied to the inter-dental embrasures of candidates and further removing excess wax using a scalpel. The wax may subsequently be removed and measured. In an experiment, twelve (12) measurements at six (6) different sites were taken (each time lingual vs buccal). The measurements indicated that the average width of the base of the embrasures appears to be 3.42 mm, the average height 4.47 mm and the average depth 3.60 mm.

Accordingly, the modified bristles 20 may comprise a width of approximately 3.5 mm, thereby allowing the other bristles to cover the gingival portion of the tooth, as shown in FIG. 13.

The modified bristles 20 and full-length bristles 30 are distributed to resemble a pattern similar to a peanut shell or a FIG. 8. To achieve this, the classic distribution of bristles was modified by shortening the length of two units of bristles near the sides 12 of the toothbrush 10 or, more specifically, in the rows that are lateral of the center row. Looking at the toothbrush head 10 from above, the distribution may be bilaterally symmetrical.

In certain embodiments, the toothbrush head 10 may comprise modified bristles 20 near the center 14 of the toothbrush head 10 along the lateral axis. The location of modified bristles 20 near the center 14 may allow for better plaque removal while brushing by removing pressure on the dental papillae, thereby allowing the modified bristles 20 and bristles 30 to better adapt to the surfaces targeted and permitting easier access to the crevasses to be cleaned. Referring to FIGS. 1 and 3, the modified bristles 20 may be located near an anterior third of the toothbrush head 10.

In particular, the modified bristles 20 near the center portion 14 of the toothbrush head 10 are configured to form a cavity shaped or modeled to form a negative cavity of the natural shape of the anterior incisors in humans which form a rounded heel, as shown in FIG. 9. The reduction of bristles at this end of the toothbrush head therefore makes it possible to better englobe said rounded heel while also better reaching the cavitation resulting from these anterior incisors. This area, which is at risk for initial tartar formation, may therefore be better cleaned as a result of this bristle arrangement.

More specifically, it may be appreciated that the modified bristles 20 near the central position 14 and near the distal tip of the toothbrush head 10, being shorter in length than the surrounding bristles 30, may allow these surrounding bristles 30 to further extend as the modified bristles 20 come into contact with a tooth surface. Accordingly, the surrounding extended bristles 30 may be better suited to clean the pits and fissures of the teeth.

Said configuration may additionally prevent the formation of tartar in crevasses. In particular, the cavity being shaped according to the negative of the anatomical heel of the lingual surfaces of the anterior teeth may allow the surrounding bristles 30 to penetrate or reach into the crevasses bordering the heel in order to prevent the stagnant plaque from forming tartar. The benefits of the present invention may therefore be appreciated as the removal of this stagnant plaque by the surrounding bristles 30 is primordial to the prevention of periodontal diseases.

In contrast, prior art toothbrush heads comprise bristles which may immediately slip upon first contact with the surface of a tooth, resulting in the bristles bending outwardly and thereby failing to reach and clean the pits and crevasses targeted by the present invention.

The positioning of the modified bristles 20 on the toothbrush head 10 may be determined in accordance with the cavitation and the dimensions of natural teeth (see, for example, FIG. 9), as the shapes are identical between the top and the bottom in the same person and vary little between humans. Accordingly, a width of approximately 3.2 mm should be suitable for the majority of dental incisor heels.

In other embodiments, the modified bristles 20 near the center 14 of the toothbrush head 10 may form a cavity configured to receive a desirable quantity of toothpaste prior to brushing. The presence of this cavity near the center 14 of the toothbrush head may additionally allow for an even distribution of the toothpaste across the modified bristles 20 and full-length bristles 30 thereby ensuring a more effective brushing of the teeth.

The present invention was successfully tested and scientifically confirmed to perform better that currently available commercial toothbrush heads.

In an observational design test using 30 candidates, several commercially available toothbrushes and the toothbrush head 10 of the present invention were tested. Said observational test indicates the percentage of residual plaque removed following brushing, as measured using the O'Leary method. The results indicate that the toothbrush head 10 performed better in removing residual plaque. An improvement of approximately 4% in cleaning performance against the mean of the others provides evidence of better cleaning performance.

The following are the tabulated results of the aforementioned test indicating the percentage of residual plaque removed following use.

O'Leary Plaque Score Toothbrush Head Type (%) BAD 17.0 GUM 491 20.0 GUM 517 21.9 GUM 525 18.9 Henry Schein 19.8 Present invention (toothbrush head 10) 23.0 Oral B 21.2 Mean (average) 20.4 (±1.7)

While illustrative and presently preferred embodiments of the invention have been described in detail hereinabove, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.

REFERENCES

-   1. C., V. L., Toothpaste, ed. L. A. Huysmans M. C. D. N. J. M.,     Weber H.-P. Vol. 23. 2013:

Monographs in Oral Science. 158.

-   2. Loe H., T. E., Jensen S. B., Experimental gingivitis in man. J     Periodontol, 1965. 36: p. 177-88. -   3. Brothwell D. J., J. D. K., Hawkins R. J., An update of mechanical     oral hygiene practices: evidence-based recommendations for disease     prevention. J Can Dent Assoc, 1998 April 64(4): p. 295-306. -   4. Ebel S., B. H., Weik U., Margraf-Stiksrud J., Deinzer R. High     Plaque Levels after Thorough Toothbrushing: What Impedes Efficacy?     JDR Clin Trans Res., 2019 Apr. 2: p. 135-142. -   5. Valm A. M., The Structure of Dental Plaque Microbial Communities     in the Transition from Health to Dental Caries and Periodontal     Disease. J Mol Biol., 2019 July 431(16): p. 2957-2969. -   6. Reichart P. A., D. U. M., Triadan H., Vickendey G. Periodontal     disease in the domestic cat. A histopathologic study. J Periodontal     Res., 1984. 19: p. 67-75. -   7. Archana V., Calculus detection technologies: where do we stand     now? J Med Life., 2014. 7(Spec Iss 2): p. 18-23. -   8. Aghanashini S., P. B., Mundinamane D. B., Apoorva S. M., Bhat D.,     Lalwani M., A Comprehensive Review on Dental Calculus. J Health Sci     Res., 2016. 7(2): p. 42-50. -   9. Carranza's, Chap 11, in Clinical Periodontology, 9th. ed p. p.     183. -   10. Loe H., Oral hygiene in the prevention of caries and periodontal     disease. Int Dent J, 2000. 50(3): p. 129-39. -   11. Frandsen A., Mechanical Oral Hygiene Practices:     State-of-the-Science Review, in Dental Plaque Control Measures and     Oral Hygiene Practice, K. D. Loe H., Editor. 1986, IRL Press:     Whashington, DC. p. 96-116. -   12. Lang N., A. R., Loe H. Proceedings of the European Workshop on     Mechanical Plaque Control. in Workshop on Mechanical Plaque     Control. 1998. Quintessence Publishing Co., Ltd. -   13. Ashley P., Toothbrushing: why, when and how? Dent Update., 2001     January-February 28(1): p. 36-40. 

1. A toothbrush head, being connected to or connectable to a toothbrush grip handle, the toothbrush head comprising: a face having longitudinal and lateral axes; and a plurality composed of a first, a second and a third type of tufts of bristles extending perpendicular to the face and each having a length; wherein: the first type of tufts of bristles is located close to a lateral side of the face along the lateral axis; the second type of tufts of bristles is located close to a center of the face along the longitudinal axis; the third type of tufts of bristles is located in areas of the face not comprising the first or second types of tufts of bristles; and the first and second types of tufts of bristles have shorter lengths than the lengths of the third type of the tufts of bristles.
 2. The toothbrush head of claim 1, the third type of tufts of bristles encircling the second type of tufts of bristles.
 3. The toothbrush head of claim 1, the length of the third type of tufts of bristles being at least 1.0 cm.
 4. The toothbrush head of claim 1, the first type of tufts of bristles having a shorter length than the second type of tufts of bristles.
 5. The toothbrush head of claim 1, the bristles of the first type of tufts of bristles having a width between 3.2 mm and 3.5 mm.
 6. The toothbrush head of claim 1, the bristles of the second type of tufts of bristles having a width between 3.2 mm and 3.5 mm.
 7. The toothbrush head of claim 1, the toothbrush head comprising four tufts of bristles of the first type.
 8. The toothbrush head of claim 1, the toothbrush head comprising four tufts of bristles of the second type.
 9. The toothbrush head of claim 1, the tufts of bristle of the second type defining a triangular cavity encircled by the third type of tufts of bristles.
 10. The toothbrush head of claim 9, the triangular cavity being from 1.5 to 2.5 mm deep compared to the length of the longest tuft of bristle of the third type and being from 2.0 to 4.0 mm long along the longitudinal axis.
 11. The toothbrush head of claim 9, the cavity being about 1.0 mm deep from the length of the longest tuft of bristle of the third type and being about 2.0 mm long along the longitudinal axis.
 12. The toothbrush head of claim 1, the location of the first and second types of tuffs of bristles being symmetrical about the longitudinal axis.
 13. A method for effectively brushing teeth, the method comprising: applying toothpaste in a cavity of a toothbrush head, the cavity being located near a distal end of the toothbrush head and made by extending tufts of bristles encircled by longer extending tufts of bristles, the longer extending tufts of bristles being configured to prevent slipping upon contact with the tooth; pressing the tufts of bristles comprising the toothpaste over teeth; and brushing for at least 30 seconds.
 14. The method of claim 12, the method further comprising: removing any applied toothpaste protruding out of the cavity prior to pressing the tufts of bristles over the teeth.
 15. The method of claim 12, the method further comprising: stopping the brushing when the fluoride concentration of the toothpaste over brushed teeth is between 250 to 500 ppm. 